1. Field of the Invention
This invention relates generally to surgical instrumentation and, more particularly, to a retractor adapted for use with endoscopic or laparascopic devices commonly used for performing examinations or surgical procedures within body cavities.
2. Description of the Prior Art
Endoscopic or laparascopic procedures are characterized by the provision of an elongated cannula structure having a relatively thin diameter with a proximal and distal end. The distal end is passed through the surrounding tissue into the body cavity wherein the surgical procedure or examination is to be effected, thus providing a conduit for the insertion of surgical instrumentation. A plurality of cannula structures may be used to allow operation of a variety of instruments simultaneously during a given procedure. For example, one cannula may provide a conduit for an endoscope for vision and illumination within the operative cavity while other cannulas provide conduits for control of specialized surgical instruments designed for performing specific procedural functions.
In conventional surgical procedures the function of holding tissue and organs in a given location to facilitate access and viewing is accomplished by a retractor. This instrument is ordinarily in the form of a broad paddle structure or multiple fingers attached to a handle. See, for example, U.S. Pat. No. 3,467,079 (James) This structure however, is not usable in laparascopic procedures since the retractor is too large to be inserted through the cannula structure into the operative body cavity.
Collapsible intralumen expanders or retractors have taken the form of radial fingers which are activatable to extend relative to each other upon entering the body cavity. See, for example, U.S. Pat. Nos. 4,654,028 (Suma), 4,459,978 (Kotsanis). Dilators of this type are also known. See, e.g., U.S. Pat. Nos. 1,328,624 (Graham) and 972,983 (Arthur). In each case, once the retractive or dilatory function is completed, the fingers are compressed and withdrawn. Another collapsible retractor structure includes a pair of collapsible fingers joined by a web of resilient material which, upon insertion into the cannula structure, can expand to form a retractive structure. See, for example, U.S. Pat. No. 4,190,042 (Sinnreich).
Such collapsible structures have certain inherent drawbacks associated therewith. For example, upon retraction loose tissue may become caught within the fingers and cause unintentional trauma to retracted tissue. Also, where the tissue is not readily dislodged, collapsing and withdrawing the retractor may be difficult and complicated.